1. Field of the Invention
This invention relates generally to the field of water treatment, and more particularly to a machine and method for removing dissolved gases from liquids.
2. Description of Prior Art
Liquids such as potable water supplies may contain unwanted dissolved gases such as radon and hydrogen sulfide. There is a need to remove these gases to improve the quality, esthetics and potability of water with a minimum of expense and plumbing without the creation of contaminated filtering media needing future disposal. Similar problems exist in various industrial processes where dissolved gases must be removed from liquids.
The prior art for removal of dissolved gases includes aeration and filtering. Aeration has been achieved by injection of a stream of air or other gas into the liquid, either by mechanical agitation of the liquid or by spraying the liquid into itself. Aeration requires a vessel with means to increase the effective liquid/gas surface area and subsequent transport of the dissolved gas out of the liquid. Filtering uses media such as activated charcoal, which adsorbs the unwanted contaminants by virtue of its large effective surface area and structure.
Examples of the prior art are found in the following U.S. patents:
U.S. Pat. No. 5,660,721 Apparatus For Treatment Of Well Water Provided Through A Well Water Supply Line PA0 U.S. Pat. No. 3,784,008 Ozonating Apparatus For Drinking Water PA0 U.S. Pat. No. 4,508,545 Closed Loop Water Treating System And Method PA0 U.S. Pat. No. 4,526,692 Process For Purification Of Contaminated Groundwater PA0 U.S. Pat. No. 4,582,610 Well Water Aeration System PA0 U.S. Pat. No. 4,608,163 Apparatus For Purification Of Contaminated Groundwater PA0 U.S. Pat. No. 4,659,463 System To Remove Contaminants From Water PA0 U.S. Pat. No. 4,756,724 Extracting Radon Gases From A Domestic Water Supply PA0 U.S. Pat. No. 4,798,034 Method And Apparatus For Collecting And Discharging Radon Gas And Fluids PA0 U.S. Pat. No. 4,843,786 Enclosure Conditioned Housing System PA0 U.S. Pat. No. 4,869,832 Radon Removal Method PA0 U.S. Pat. No. 4,957,394 Method And Apparatus For Sub-Floor Collection And Disposal Of Radon Gas PA0 U.S. Pat. No. 4,988,237 Soil Gas Reduction System PA0 U.S. Pat. No. 5,003,750 Method For Reducing Immunogenic And/Or Toxic Substances In Indoor Air PA0 U.S. Pat. No. 5,045,215 Removing Hazardous Contaminants From Water PA0 U.S. Pat. No. 5,100,555 Method And System For Removing Radon From Radon Containing Water PA0 U.S. Pat. No. 5,104,554 Removing Radon By Downhole Sparging Of Air PA0 U.S. Pat. No. 5,107,642 Arrangement In Screening Of Objects, Especially Residential Houses PA0 U.S. Pat. No. 5,143,606 Arrangement For Cleaning Contaminated Ground Water PA0 U.S. Pat. No. 5,147,530 Well Water Removal And Treatment System PA0 U.S. Pat. No. 5,149,343 Method For Filtering Radon From A Gas Stream PA0 U.S. Pat. No. 5,194,158 Radon Removal System And Process PA0 U.S. Pat. No. 5,279,746 Process And Apparatus For Removing Radon From Water PA0 U.S. Pat. No. 5,354,459 Apparatus And Method For Removing Odorous Sulfur Compounds From Potable Water PA0 U.S. Pat. No. 5,403,234 Radon Gas Evaluation System And Method.
Shortcomings of the prior art are its complexity, size, and cost. Aeration as described in the above citations requires secondary pumps scaled to the main supply pump, large reaction vessels and elaborate piping. In addition, these systems do not contain provision for control of the degassing process by sensing the exhaust contamination level.
Approaches using activated charcoal or other filtering media suffer from the limited capacity of the filtering media, the need to recharge or replace it and the attendant cost. Recharging of filtering media contaminated with gaseous contaminants generally requires removal of the media to a recycling facility and the use of chemical cleaners or elevated temperatures, all of which are difficult or impossible to employ on-site.